151 



list of the species is from the last edition of Lamarck. A monograph of 

 the genus is much needed. 



1. acicula, Sow. 



2. acuta, Desm. 



3. alba, Forbes. 



4. arata, Recluz. 



5. Bruguierei, Payraud. 



6. Bryerea, Macgill. 



7. Buccinoides, Desk. 



8. cancellata, Recluz. 



9. Chesnetii, Michaud. 



10. cingillata, Macgill. 



11. cingulus, Michaud. 



12. costata, Recluz. 



13. crenulata, Michaud. 



14. cyclostoinata, Recluz. 



15. deformis, Sow. 



16. Deshayesiana, Recluz. 



17. Desmarestii, id. 



18. elongata, P/m7. 



19. excavata, id. 



20. fragilis, Michaud. 



21. fulva, w?. 



22. Gougeti, id. 



Species. 



23. gracilis, Macgill. 



24. grossa, Michaud. 



25. Guerinii, Recluz. 



26. hyalina, Desm. 



27. Inca(Pmom«),D'Or. 



28. interrupta, Johnston. 



29. labiata, PM 



30. lactea, Michaud. 



31. lilacina, Recluz. 



32. lineolata, Michaud. 



33. marginata, z'^. 



34. Matoniana, Recluz. 



35. niinutissinia, .M-m;^. 



36. monodonta, P/«7. 



37. Montagui, Payraud. 



38. muriatica, Macgill. 



39. oblonga, Desm. 



40. parva, Recluz. 



41. praeusta, zV?. 



42. pidcbella, PM 



43. punctulum, «J. 



44. puncturata, Macgill. 



45. pusilla, Ztes/*. 



46. pygmsea, Michaud. 



47. radiata, P/m7. 



48. reticulata, -Sow. 



49. rubra, Macgill. 



50. scalaris, Michaud. 



51. semistriata, Johnston. 



52. spirata, #020. 



53. Souleyetana, Recluz. 



54. striata, Q«oy. 



55. striata, Macgill. 



56. striatula, Recluz. 



57. subumbilicata, iiae. 



58. tridentata, Michaud. 



59. tristriata, Thompson. 



60. tnmcata, Macgill. 



61. ulvae, zrf. 



62. uuifasciata, Recluz. 



63. ventricosa, Desm. 



64. ventricosa, Macgill. 



65. violacea, Desm. 



66. vittata, Recluz. 



Figure. 



Rissoa Cumingii. PI. 15. Fig. 75. Shell, showing the aperture with 

 its thickened lip and sinuated formation at the upper part. 



Family 8. PLICACEA. 



Shell ; distinguished by having the columella strongly plaited and 

 the base entire without indication of any sinus, the animal 

 being of marine habits, and furnished with a horny operculum. 



Little is known of the soft parts of this family beyond the external form 

 of Pgramidella described by M. Quoy in the ' Voyage de 1' Astrolabe*. ' 



* Comme on le voit, rien n'est encore connu sur l'organisation interieure des PyramideJles ; 



